javascript - Behavior of html form onsubmit event in JSFiddle -

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i have simple form has nothing other submit button. want prevent submission of form (i know doesn't make sense illustration). i'm making use of form's onsubmit event , event returns false. work 'incomprehensible behavior' arises.

i can associate return false; statement onsubmit event of form either using inline javascript or keep in different place.

<form onsubmit="return false;" id="form1" method="post">     <input type="submit" id="btnbutton" value="submit" /> </form>

now, aforementioned code works fine. see => http://jsfiddle.net/mcck5/

i can modify above code follows in order make javascript separate (unobtrusive).

--some html markup <form onsubmit="return falsifier()" id="form1" method="post">     <input type="submit" id="btnbutton" value="submit" /> </form>  <script>     function falsifier() {     return false; } </script>   --other html markup follows

here, script tag placed right after form in html markup. works too. see => http://jsfiddle.net/afdq5/

but when shift javascript different place (ex: external file), doesn't seem work.

by taking console in inspect element, noted error falsifier not defined.

see here => http://jsfiddle.net/5cr5r/2/

could elaborate on why so?

you're encountering design feature (or flaw) in jsfiddle:

in jsfiddle, "javascript" pane not direct source code of referenced javascript file, instead jsfiddle wraps code below , inserts <head>. go view source see does:

<script type='text/javascript'>     //<![cdata[      window.onload=function(){         function falsifier() {             return false;         }     }     //]]>   </script>

your <form> elements can't find falsifier because falsifier exists within scope of anonymous function.


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